"Kek", from "kekeke"/"???", a Korean onomatopoeia of laughter utilized in the same way to "LOL", would be the Korean equivalent of your English "haha". Given that this is often Employed in StarCraft matches, Blizzard, Starcraft’s developers, chose to reference it in Wow (2004): whenever a participant in the Horde faction styles "lol" using the /s